Device for evacuating and filling vessels by means of pressure



Mayrl3, 1952 E. w. JQHNsoN DEVICE FOR EVACUATING AND FILLING VESSELS BY MEANS OF PRESSURE Filed Nov. 17, 1948 1N V EN TOR. fm e W, Joh/won A 7 TOR/VEYS Patented May 13, 1952 DEVICE FOR EVACUATING AND FILLING YESSELS BY MEANS 0F PRESSURE Ernest WfJohnso, mountainside, N. J. Application November 17, 1948, Serial N o. 60,546

3 Claims.

This invention relates to a device for evacuating vessels `such as those generally found in laboratories and more particularly to a device for controlling the vacuum applied to such vessels. While not limited thereto, the device will be described for illustrative purposes in connection with the evacuating of pipettes in order to lill the latter with liquid, the liquid, of course. entering the pipette as vacuum is applied.

Broadly speaking, the invention comprises an open-ended tube and a second tube slidably enclosing or surrounding the same. The second tube has an opening adjacent its upper end which serves to establish communication on its inner side with the first tube and on its outer side with a source of vacuum. By sliding the second or outer tube relatively to the first tube, the opening can be moved into and out of communication with the rst tube. Means are also provided for tensionally supporting the second tube about the iirst such that the opening is normally in communication with the first tube, thus exposing the latter to the vacuum source.

The invention may be better understood by referring to the accompanying drawing in which a preferred embodiment of the invention is illustrated and in which:

Fig. 1 is a broken, partially sectioned, side elevational View of the device;

Fig. 2 is a partially sectioned view similar to Fig. l but showing the tubes in a different position relatively to each other; and

Fig. 3 is a sectioned and partially broken away view of Fig. 1, the section being taken along the line III-III.

As seen in Fig. 1, I0 is an open-ended inner tube slidably disposed within a second or intermediate tube or sleeve Il. Adjacent its open upper end I2 the tube II is provided with an opening I3 which on its outer side communicates through connection I4 with a source of vacuum, not shown. By vacuum" is meant a condition of low pressure which is always less than atmospheric. On its inner side the opening I3 is in communication with the tube I0 and the atmosphere. Tube II extends longitudinally of tube Ill and downwardly thereof to a point intermediate the ends of tube I0, as indicated at I5. Tension means in the form of compression spring I 6 supports and acts against the lower end I5 of tube II to position the tube relatively to tube I0 in the manner generally shown in Fig. l. In this relative arrangement of the tubes the upper end I'I of tube I0 is in communication with the vacuum source through connection I4. Lower 2 end I8 of tube I0 is connected through a length of iiexible tubing I9 to a space to be evacuated, which in the present case is defined by the pipette 20, the upper end of which is shown at 2I and the body or reservoir at 22.

Spring I6 is supported on the tube IIJ by suitable means, which in the form shown comprises an external annular shoulder 23 adjacent the lower end of the tube.

A third or outer tube or sleeve 24 surrounds the tubes I0 and II and spring I6 and aids in supporting the latter. In effect, sleeve 24 connes the spring to operation within the annular space 25 between the inner and outer tubes (Fig. 3). Sleeve 24 is securely fastened at its lower end to the shoulder 23. The upper end of the sleeve is open, and the tube II is slidably movable therein. As is evident, the spring acts to move the tube II upwardly, and in this connection sleeve 24 also serves to restrain the upward movement of tube II at a point where the connection I4 is above the upper end I'I of tube I0, in other words to maintain tube Il) in communication with connection I4. For this purpose means are provided on sleeve 24 in the form of slot 26 to cooperate with other means on the tube II in the form of the projection or lug 21. As will be apparent, the latter moves up and down in slot 26 as tube II is moved relatively to the tube I0 and sleeve 24. Downward movement of tube II is brought about manually, as will be later described, and upward movement is effected by the uncoiling of spring I6. The latter movement is checked by engagement of projection 2l with the stop portion 28 at the upper end of the slot.

To operate the device, the tubing I9 is connected to the end 2| of the pipette 20 and the connection I4 is connected to a source of low pressure. such as, for example, an aspirator. The tip or nozzle end (not shown) of the pipette is immersed in the usual way in a reservoir or container of the liquid to be drawn into the pipette, and then the operator seals the upper end I2 of tube I I by placing his index linger thereover, thus enabling liquid to be forced upwardly in the pipette. In this manoeuvre the device may be supported by grasping sleeve 24 between the thumb and second linger, and the index iinger is gently but iirmly held over the end of tube I I. When the liquid in the pipette reaches a point between the mark 29 and the upper end 2 I, tube II is pressed downwardly by the index linger against the action of spring I6 until the vacuum is cut oiT by virtue of the fact that opening I3 passes below the upper end of tube II), as shown in Fig. 2. In this position, air may be admitted to tube I 0 by manipulating the index finger covering the upper ends of tubes I0 and ll, i. e. by slightly raising the finger, and in this way the liquid level in the pipette may be lowered until it coincides with the mark 29. The pipette may then be removed from the container and its contents discharged by simply removing the index fingvfrm'contact with the ends ofvtubes l0 and H. Y

While the invention has been described and illustrated in connection with a more or less specie embodiment thereof, it-wil l lbe appreciated that it is capable of obvious Variations'without departing from its scope.

In the light of the foregoingfde'scription; the Y Y following is claimed:

1. A manually operable hand device ofthe character described comprising an open-'ended inner tube, an intermediate tube slidably surrinding'said'iner tube* and having a'vacuum -cniictiorraijacentitheiupper end thereof; spring Trfz'iear'i's supported?on-theiinner 'tube and acting 'a'gainstithe intermediate tubeto `move the latter upwardly7 relativelylto. theinnerftube,` an outer i f sleeve'- surrounding'sai'd spring i means, and coopleratinglinlfzans"joni said sleeve" and intermediate --`-tube'lfor'=limiting'upward movement of the intermediate tube at a pointlv'vh'ere the innerv tube llis-inf' ccnimunic'ation`v with 'the vacuum connection g 'of-ftheV intermediate tube.

ZRT-Affanual'ly operableV hand device offthe IV`f'zlis'alracteridescribed comprising an open-ended inner tub'ean v intermediate `tuloeconcentric with Vthe innerV tube.

and slidably surrounding said inner tube and having avacuum connection adjacent the upper end thereof, an outer tube surrounding both said inner and intermediate tubes and fastened at the lower end thereof to the inner tube, said intermediate tube being slidable in the upper portion of the outer tube, and tension means supported by the outer tube and acting against the intermediate tube,- 'sai'd tension:orleans serving to position theintermediate tube Vrelatively "to "the inner tube so that the vacuum connection of the intermediate tube is normally in communication with 33. Iniafdevice ofv the character described, an open-ended tube, a second tubeA slidably surrounding saidfiirst tube and having a vacuum iconnectionadjacent the upper end thereof, said second tube being movable longitudinally of the lrsttubeto bring the latter into and out of communication with the 'lvacuum connection, and tension means suppbrt'edl about thelnr'stitube"r 'for vnormally maintaininglthe second'ltubepositioned relatively-'to the iirsttubefsuch 1thatplltheilaltterl'is "in comnfiunication` -lwitli the? vacuumi-oonnection Y rfitnFnRmNcEscI'rnD .Y n The" following" references "are of "record 'inthe file of this palt'er'i'tV 

